This invention relates to computerized processes for financial planning for individuals and groups whose financial portfolio would be subject to tax on certain events. More, particularly, this invention is a method for transforming the usual pretax information for calculation of an efficient frontier, unique to an investor's portfolio, in such a manner that any portfolio on the calculated frontier is efficient after incorporating the effect of taxes on the risk and expected return of each asset class permitted in the investor's portfolio. In this context an “efficient frontier” is the set of all efficient portfolios. An after-tax efficient portfolio is one that provides the greatest expected after-tax total return for a given level of after-tax risk. In order to structure a portfolio for an individual investor, one must take the effects of taxes into account, since taxes levied on investment outcomes, typically on income and realized capital gains, may have an important impact on net portfolio results.